Flip Flop Locking Question

Discussion in 'Motorized Bicycle General Discussion' started by xetaprime, Sep 4, 2011.

  1. xetaprime

    xetaprime New Member

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    So yeah my initial excitement as a noob is off a bit. I now get that a fixie sprocket would probably not handle well even with a lock nut. But, what if I added some kind of bearing sleeve between the lock nut and the inside stay axel plate? wouldn't that stop the nut and sprocket from going anywhere? It would have no where to go and wouldn't affect the outside axel nut? Couldn't you even use large washers as spacers?

    [​IMG]

    Best,
    Xeta
     
    #1 xetaprime, Sep 4, 2011
    Last edited: Sep 4, 2011
  2. decoherence

    decoherence New Member

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    i haven't seen the hub but, would drilling a hole & putting a cotter pin in work?
     
  3. xetaprime

    xetaprime New Member

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    That's a good idea. The lock nut has notches where pins might go which would stop it from unscrewing. Hmmmm.... and of course I forgot that the whole lock nut 'itself is rotating which would if it comes loose would press the sleeve and cause wear and friction! OY! I like the pin idea :)
     
    #3 xetaprime, Sep 4, 2011
    Last edited: Sep 4, 2011
  4. xetaprime

    xetaprime New Member

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    So here's what I'm thinking now. I can't wait for the engine to arrive so I can hold the stock sprocket in my hands though.

    I want to bolt the kit sprocket to my existing fixed sprocket drilling holes where the fixie cog indentations are and put pins/bolts where the lockring indentations are. Possible?

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  5. DuctTapedGoat

    DuctTapedGoat Active Member

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    Don't try to use a flip flop - it won't hold up.

    If you're intent on finding a solid way to mount - you should go with a disc brake mounted sprocket.
     
  6. xetaprime

    xetaprime New Member

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    What won't hold up? Meaning the lockring unscrewing? I''ve got a plan and another plan but I'll know more once the engine arrives. Did you mean something else?
     
  7. DuctTapedGoat

    DuctTapedGoat Active Member

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    There's not enough threads on any flange you'll find for your sprocket.

    If you were to just use a freewheeling sprocket that was southpaw, to start you'll need a pull start to start it, but you won't be able to use the lock riing.

    Flip flop hubs are no bueno - that's why I say to use a disc hub.
     
  8. xetaprime

    xetaprime New Member

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    That makes sense and I understand. But my plan is to attach the stock 40T to the fixed sprocket and lock the lockring. I posted a picture elsewhere but I'll show it again for why not.

    [​IMG][/URL]
     
  9. xetaprime

    xetaprime New Member

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    Hey y'all! Just a quick note nefore I start filing away. Got the 80cc engine yesterday. Not too happy with some things but that's another story. The good news is the photo I put together above was heaven sent. The fixie sproket ndents do align with the 40T holes Yay! I'll post some pictures soon. I just have to file a tiny bit of the 40T center hole to fit over the lip on the fixie cog. Boy I got lucky!
     
  10. DuctTapedGoat

    DuctTapedGoat Active Member

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    Best of luck to ya on it xeta - I'm sorry if I sound like a raincloud on your picnic, I did a fair amount of fiddling around with a flip flop wheel, and there wasn't much that could be done without welding. Biggest thing I would suggest to you is to be absolutely certain that the sprocket has as many threads as possible so as to prevent stripping out the sprocket or the hub.
     
  11. xetaprime

    xetaprime New Member

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    Hi, have you ever stripped out the threads? Most I've heard is the lockring will come loose but I'm planning on putting a lock on the lockring.

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  12. DuctTapedGoat

    DuctTapedGoat Active Member

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    I ended up going with a "dual drive" hub, it's like a flip flop, but with reversed threads on the left, so you can run two drivechains, both threaded tight on the hub. That's the one I blew the threads out on - from which I'm sure you can see why I worry when the threads are being torqued even more when doing that set up on a flip flop hub.
     
  13. xetaprime

    xetaprime New Member

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    Party pooper but I thank you for the info. Tweaking my plan then. I found earlier that I had to reverse the sprocket and have the stock 40T curve inwards other wise it wasn't aligned and the bolts were rubbing agaisnt the stays.

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    I'm planning to add a screw in the locking indents on the lockring to stop it from unscrewing and I think I can have it go straight through to the hub. Maybe three of them. **** if I know.

    But I hear what you are saying.
    Best to you,
    Xeta
     
  14. xetaprime

    xetaprime New Member

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    DTG, can I ask, did you do what I did and attach sprocket to cog or use a threaded smaller cog directly? Would very much like to know what you did. I'm of course just trying to use the darn wheel that came with the bike. I'm temped to fill all threads with PC7 and if I have to replace the whole wheel later which I might have to do anyway??? My flanges are small so not much room to run anything all the way through. hmmm... P.S. Not intending to run this bike fast. Just need it for local shopping. 20mph would be fine for me.
     
  15. xetaprime

    xetaprime New Member

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    Adding a new idea. I put a few matching opposed notches on the hub threads and the cog/sprocket itself. Screw on the sprocket, insert pins into notches and that thing should not turn... maybe (sigh) :)
     
  16. DuctTapedGoat

    DuctTapedGoat Active Member

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    You're definitely on the right track - the sprocket and flange I was using was freewheeling. I had the idea to do removable pins in the bearing casing, but ended up just JB Welding the bearings to frozen. Of course, the reversed threads on the motor side of the hub is a different dynamic than what you're doing, but the pins is a good way to go about it, it should give the proper reinforcement to hold strong to the high torque low rpm side of these motors.

    Best thing I could ever think was to weld a flange to the hub and bolt on and off the sprocket directly from the hub. A flip flop seems like it'd be a good candidate for this, but I haven't ever welded anything more than printed circuit board and wires (soldering :D ). Welding the lock nut and sprocket/flange to the hub is a good way to get things started. It's in essence the same concept as the disc brake hub, but without having to go purchase an all new back end.
     
  17. xetaprime

    xetaprime New Member

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    Ha! Because of your stripped hub mention I googled this crappy hub I have. It's a quando and apparently will strip under pedal power wear! OY! So I will have to do more to this thing for sure. My one concern is finding a way to be able to undo whatever I decide to do. Or, just make it permanent like welding, and just buy a new everything if the wheel collapses and I survive it all.

    Still, it is fun thinking so much ;)

    Regards,
    Xeta
     
  18. DuctTapedGoat

    DuctTapedGoat Active Member

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    No matter what - it's a blast just for the ride, no matter how long it lasts! It's a fun one to think about, gave me many a headache, but many a good inspiration.
     
  19. xetaprime

    xetaprime New Member

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    >R.I.P.<
    Staton Inc. Aluminum Dual Threaded Hub.
    Born : 1 - 10 - 11
    Died : 4 - 16 - 11

    My googles lead me to you hub pics :( Yes, no matter what, is is a blast for sure!
     
  20. xetaprime

    xetaprime New Member

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    New plan (sigh sorta). JB Weld. Plan was to JB Weld the sprocket on, drill holes for pins and JB the lockring. The fixie sprocket is tough man! All I managed to do was drill into the hub but I'm pretty sure that messed up the threads, ya think, so that with the JB and all threads covered, inside and out, sprocket and lockring, this might hold. At least now, I can start thinking about attaching the motor etc. Pictures coming soon.

    Best to all, Xeta
     

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